1. Field of the Invention
This invention is directed to an injection valve typically used in conjunction with an injection well. Injection wells are drilled for example in close proximity to producing oil or gas wells that have peaked in terms of their output. Fluid for example water is pumped under pressure into the injection well which in turn acts to force the oil or gas into the producing wells thus increasing the yield.
2. Description of Related Art
U.S. Pat. No. 7,966,401 discloses an injection safety valve having a restrictor to create a pressure differential so as to move a flow tube past a flapper valve. The diameter of the restrictor if fixed.